AKM AK4250VU Output coupling capacitor-less video amp with lpf Datasheet

ASAHI KASEI
[AK4250]
AK4250
Output Coupling Capacitor-less Video Amp with LPF
GENERAL DESCRIPTION
The AK4250 is a Video Amp with LPF. The output coupling capacitor can be removed because the
AK4250 includes the negative power supply circuit. The AK4250 is housed in a space-saving 8-pin
USON package.
FEATURE
1. Video Function
• A Composite Video Input
• A Video-Amp (+6dB) for Composite Video Signal
• Low Pass Filter
• Charge pump circuit for negative power supply
2. Ta = -40 ∼ 85 °C
3. Power Supply: 2.7 ∼ 3.6V (typ. 3.0V)
4. Power Supply Current: 10 mA
5. Package: 8 pin USON
■ Block Diagram
PDN
VIN
Clamp
VOUT
LPF
Clock
Generator
VDD
Charge
Pump
CP
CN
VSS
VEE
Figure 1. AK4250 Block Diagram
MS0540-E-00
2007/03
-1-
ASAHI KASEI
[AK4250]
■ Ordering Guide
AK4250VU
AKD4250
−40 ∼ +85°C
8 pin USON (0.5mm pitch)
Evaluation board for AK4250
■ Pin Layout
CP
1
VDD
2
VIN
3
PDN
4
Top
View
MS0540-E-00
8
CN
7
VEE
6
VSS
5
VOUT
2007/03
-2-
ASAHI KASEI
[AK4250]
PIN/FUNCTION
No.
1
2
3
Pin Name
CP
I/O
O
VDD
VIN
I
4
PDN
I
5
6
7
8
VOUT
VSS
VEE
CN
O
O
I
Function
Positive Charge Pump Capacitor Terminal Pin
Power Supply Pin.
Composite Video Signal Input Pin
Power-Down Mode Pin. Internal Pull Down 100kΩ.
“H”: Power up, “L”: Power down.
Composite Video Signal Driver Pin
Ground Pin
Negative Voltage Output Pin for Video Amplifier
Negative Charge Pump Capacitor Terminal Pin
ABSOLUTE MAXIMUM RATINGS
(VSS=0V; Note1)
Parameter
Power Supplies:
Input Current, Any Pin Except Supplies
Input Voltage
(Note 2)
Ambient Temperature (powered applied)
Storage Temperature
Symbol
VDD
IIN
VIN
Ta
Tstg
min
−0.3
−0.3
−40
−65
max
4.0
±10
(VDD+0.3) or 4.0
85
150
Units
V
mA
V
°C
°C
Note 1. All voltages are with respect to ground.
Note 2. VIN, PDIN pins. Max is smaller value between (VDD+0.3)V and 4.0V
VOUT pin becomes Hi-Z at PDN pin = “L”. Therefore VOUT pin is available to signal line from another device
by Wired-OR. The input signal to VOUT pin mustn’t exceeds this input voltage range.
Any voltage must not be applied to the CN pin.
WARNING: Operation at or beyond these limits may result in permanent damage to the device.
Normal operation is not guaranteed at these extremes.
RECOMMENDED OPERATING CONDITIONS
(VSS=0V; Note1)
Parameter
Power Supplies
Symbol
VDD
min
2.7
typ
3.0
max
3.6
Units
V
Note 1. All voltages with respect to ground.
* AKM assumes no responsibility for the usage beyond the conditions in this datasheet.
MS0540-E-00
2007/03
-3-
ASAHI KASEI
[AK4250]
ANALOG CHRACTERISTICS
(Ta=25°C; VDD =3.0V; VSS = 0V; unless otherwise specified)
Parameter
Conditions
min
typ
max
Units
V Input Characteristics
Input Voltage
1.5
Vpp
Input Sync Chip Clamp Voltage (Note 3)
-0.386 -0.286 -0.186
V
V Output Characteristics (Note 4)
Output Gain
VIN=100kHz, 0.2Vpp
5.0
6.0
7.0
dB
Maximum output voltage
VIN=100kHz , THD=-30dB
2.52
Vpp
65
dB
S/N
BW=100kH ∼ 6MHz, (Note 5)
Secondary Distortion
VIN=3.58MHz, 0.2Vpp (Sin Wave)
-45
dB
Load Resistance
140
150
Ω
15
pF
Load Capacitance
C1 (Figure 2)
400
pF
C2 (Figure 2)
LPF
Frequency Response
Response at 6.75MHz
-3
-0.5
dB
Input= 0.2Vpp, Sin Wave
Response at 27MHz
-40
-20
dB
(0dB at 100kHz)
Group Delay
|GD3MHz - GD6MHz|
10
100
nsec
Power Supplies
Power Up
Black signal is output and no load
10
15
mA
resistance.
Power Down
PDN pin = 0V
1
20
μA
Note 3. The Charge Pump circuit doesn’t work well, if the sync chip clamp voltage input to VIN pin isn’t within this
voltage range. This sync chip clamp voltage is the voltage from the pedestal voltage
Note 4. The measurement point is the point A in Figure 2
Note 5. The reference signal is the 100% white signal.
Measurement Point A
75 ohm
Video Signal Output
R2
75 ohm
R1
C1
C2
Figure 2. Load Capacitance C1 and C2
DC CHRACTERISTICS
(Ta=25°C; VDD=2.7 ∼ 3.6V)
Parameter
High-Level Input Voltage
Low-Level Input Voltage
(PDN pin)
(PDN pin)
Symbol
VIH
VIL
MS0540-E-00
min
1.5
-
typ
-
max
0.6
Units
V
V
2007/03
-4-
ASAHI KASEI
[AK4250]
■ Video Block
The Video Amp has a drivability for a load resistance of 150Ω. The AK4250 has a composite input and output and
includes a low pass filter (LPF). Internal negative power supply circuit supplies negative voltage to the video amp and
video amp 0V output is used for a pedestal level. Therefore, the output coupling capacitor can be removed.
AK4250
VDD
Charge
Pump
CP
CN
Negative Power
VSS
(+)
1uF
C1
C2
VEE
1uF
(+)
Note 6. C1 and C2 capacitors should have the low ESR (Equivalent Series Resistance) over all temperature
range. When these capacitors have the polarity, the positive polarity pin should be connected to the CP
pin and the VSS pin. Non polarity capacitors can also be used.
Figure 3. Negative Power Supply circuit
AK4250
75Ω
VOUT
75Ω
0V
Figure 4. Video signal output
■ Power Down Control
When the PDN pin is “L”, the AK4250 is forced to the Power Down Mode (Power consumption: typ 1μA). VOUT pin
becomes Hi-Z at PDN pin = “L”. The AK4250 includes a power-on-reset function. Therefore any reset isn’t required
externally.
MS0540-E-00
2007/03
-5-
ASAHI KASEI
[AK4250]
SYSTEM DESIGN
Figure 5 shows the system connection diagram for the AK4250. An evaluation board [AKD4250] is available which
demonstrates the optimum layout, power supply arrangements and measurement results.
(+)
Power Supply
2.7∼3.6V
10µ
+
1µ
1 CP
0.1µ
CN 8
0.1u
1µ
VEE 7
2 VDD
(+)
Top View VSS 6
3 VIN
75
VOUT 5
4 PDN
DSP or μP
Figure 5. Typical Connection Diagram
Note:
- Any voltage must not be applied to the CN pin.
MS0540-E-00
2007/03
-6-
ASAHI KASEI
[AK4250]
PACKAGE
8pin USON (Unit : mm)
2.2 ± 0.05
0.25 ± 0.05
1.2 ± 0.05
2.2 ± 0.05
1.9 ± 0.05
0.05
0.5
M
0.2 ± 0.05
0.6MAX
We recommend mounting this portion onto circuit
board in order to secure mounting intensity. Please do
not connect to a Power Supply, GND, Signal Line, etc.
0.05
■ Material & Lead finish
Package molding compound:
Lead frame material:
Lead frame surface treatment:
Epoxy
Ni
Ag plate
MS0540-E-00
2007/03
-7-
ASAHI KASEI
[AK4250]
MARKING
■ AK4250VU
250
XXX
1
XXX: Date code (3 digit)
REVISION HISTORY
Date (YY/MM/DD)
07/03/28
Revision
00
Reason
First Edition
Page
Contents
IMPORTANT NOTICE
• These products and their specifications are subject to change without notice. Before considering
any use or application, consult the Asahi Kasei Microsystems Co., Ltd. (AKM) sales office or
authorized distributor concerning their current status.
• AKM assumes no liability for infringement of any patent, intellectual property, or other right in the
application or use of any information contained herein.
• Any export of these products, or devices or systems containing them, may require an export license
or other official approval under the law and regulations of the country of export pertaining to customs
and tariffs, currency exchange, or strategic materials.
• AKM products are neither intended nor authorized for use as critical components in any safety, life
support, or other hazard related device or system, and AKM assumes no responsibility relating to any
such use, except with the express written consent of the Representative Director of AKM. As used
here:
a. A hazard related device or system is one designed or intended for life support or maintenance of
safety or for applications in medicine, aerospace, nuclear energy, or other fields, in which its
failure to function or perform may reasonably be expected to result in loss of life or in significant
injury or damage to person or property.
b. A critical component is one whose failure to function or perform may reasonably be expected to
result, whether directly or indirectly, in the loss of the safety or effectiveness of the device or
system containing it, and which must therefore meet very high standards of performance and
reliability.
• It is the responsibility of the buyer or distributor of an AKM product who distributes, disposes of, or
otherwise places the product with a third party to notify that party in advance of the above content
and conditions, and the buyer or distributor agrees to assume any and all responsibility and liability
for and hold AKM harmless from any and all claims arising from the use of said product in the
absence of such notification.
MS0540-E-00
2007/03
-8-
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